Electromagnetic relay armature mounting

ABSTRACT

An L-shaped armature is mounted on a supporting yoke associated with an electromagnetic relay coil in a manner enabling easy straight line assembly and removal of the armature and assuring positive mounted retention of the armature for efficient functioning for its intended purpose. Retention of the armature is effected by a leaf spring having a generally Z-shaped portion extending through an aperture in the armature and engaging with an anchor edge aligned with the rocking fulcrum of the armature. Straight line assembly is facilitated by a cam terminal on the free end portion of the spring and a cam surface tooth formation on the armature. Interlocking shoulders on the spring and the armature assure positive retention of the armature on the yoke.

United States Patent [191 Ain et al. p

a [111 3,821,674 [451 June 28, i974 [54] ELECTROMAGNETIC RELAY ARMATUREMOUNTING [75] Inventors: Martin Aidn; Gerhard Furtwangler,

both of Munich; Eberhard Wanlka, Dachau, all of Germany [73] Assignee:Siemens Aktiengesellschaft, Berlin & Munich, Germany 22 Filed: Apr. 112,11973 21 Appl. No.: 350,3115

[30] Foreign Application Priority Data Apr. 17, 1972 Germany 2218493[52] US. Cl. 335/270, 335/274 [51] Int. Cl. H0 [58] Field ofSearch....'. 335/274, 276, 270

[56] References Cited UNITED STATES PATENTS 2,461,360 2/1949 Vincent335/274 3,365,683 1/1968 Aidn et al. 335/274 FOREIGN PATENTS ORAPPLICATIONS Germany 335/276 312,606 7/1969 Sweden 335/276 PrimaryExaminerGeorge Harris Attorney, Agent, or Firm-Hill, Gross, Simpson, VanSanten,. Steadman, Chiara & Simpson [5 7] ABSTRACT An L-shaped armatureis mounted on a supporting yoke associated with an electromagnetic relaycoil in a manner enabling easy straight line assembly and removal of thearmature and assuring positive mounted retention of the armature forefficient functioning for its intended purpose. Retention of thearmature is efvfected by a leaf spring having a generally Z-shapedportion extending through an aperture in the armature and engaging withan anchor edge aligned with the rocking fulcrum of the armature.Straight line assembly is facilitated by a cam terminal on the free endportion of the spring and a cam surface tooth formation on the armature.Interlocking shoulders on the spring and the armature assure positiveretention of the armature on the yoke.

llll Claims, 2 Drawing Figures ELECTROMAGNETIC RELAY ARMATURE MOUNTINGThis invention relates broadly to electromagnetic relays, and is moreparticularly concerned with the mounting of generally L-shaped armatureson the supporting yokes of the relays.

In the prior art, the use of retaining springs of various shapes forangular armatures is known. For example, in German Gebrauchsmuster1,805,215 an armature retaining spring is described which is insertedthrough an aperture in the armature into engagement with the yoke.However, in such construction, the armature spring must be insertedcarefullythrough the aperture in the armature and thereafter screwedonto the yoke to retain the armature. Because of the complicated shapeof the armature spring in that disclosure, therefore, the assembly mustbe effected strictly manually.

Another prior art example that may be referred to is in German publishedapplication 1,002,467 which describes an angulararmature which isretained by a metal leaf spring attached at the yoke, and with thespring extending through an opening in the middle of the armature.However, the'exact shape of the annature and the retaining spring cannotbe determined from the illustration in that prior disclosure and thedisclosure does not contain sufficient details concerning the shape andthe assembly possibilities in respect to the armature spring. Therefore,it must be assumed that the armature spring is assembledand secured inthe same manner as the first mentioned instance, that is by inserting itthrough the opening in the armature and thereafter securing the springin place on the yoke.

According to the present invention, the foregoing and otherdisadvantages, defficiencies, inefficiencies, shortcomings and problemsin electromagnetic relay armature mounting are overcome.

Another object of the invention is to provide a new and improvedarmature and retaining spring structure for electromagnetic relays, anda method of assembling the same. I

A further object of the invention is to provide a new and improvedarmature and retaining spring structure for electromagnetic relaysadapted to be assembled in a simple mechanical straight line assemblyoperation, facilitating low cost mass production.

Still another object of the invention is to provide a new and improvedarmature and retaining means therefor permitting not only quick and easymechanical assembly but also quick and easy replacement of the armature.

Yet another object of the invention is to provide a new and improvedelectromagnetic relay armature constructed and arranged forsnap-together assembly.

Other objects, features and advantages of the invention will be readilyapparent from the following description of a preferred embodimentthereof, taken in conjunction with the accompanying drawing, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts embodied in the disclosure, andin which:

'FlG. l is a perspective assembly view of an armature and magnetic relayyoke having a retaining spring thereon and demonstrating how the partscan be readily assembled by a straight line assembly action; and

FIG. 2 is a side elevational view, partially in section, of anelectromagnetic relay having an armature assembled therewith accordingto the present invention.

In a typical relay construction embodying features of the invention, asshown in the drawings, by way of illustration, a relay coil 17 hasoperatively associated therewith a yoke 1 having means in the form of aleaf spring 2 for retaining an armature 8 movably mounted on the freeend portion of an outer leg la of the yoke and in a position tocooperate with a pole lb extending through the coil l7.

ln a preferred construction, the armature retaining leaf spring 2comprises an elongated body having an inner end portion 2a secured as bymeans of an oval rivet 7 flatwise against the outer face of the yoke armla and against turning from an axially extending position wherein anopposite angular end portion finger 3 turned obliquely generally intothe plane of the yoke arm la extends into and preferably longitudinallyslightly beyond an endwise opening recess 4 in the armature-supportingend portion of the yoke arm lla.

Mounting of the armature 8 on the yoke arm la is such that the armaturecan rock between a magnetically activated and an inactive position. Forthis purpose the armature is of generally L-shaped construc tion havingan elongated leg 8a arranged to overlie the yoke arm ]la and having anysuitable preferred free end shape to serve the intended purpose, suchfor example, as for coupling such leg to a device to be actuated therebyin the rocking movements of the armature. To this end, the free endportion of the armature leg 8a may have pressed therein a spacer boss 18for engagement with the yoke arm la. At its opposite end of the leg 8a,an angular pole leg 8b normally extends in gap relation to the pole lband is adapted to be drawn theretoward to rock the armature about a linecontact fulcrum edge surface 16 on the end of the yoke arm lla engaginga bight bearing surface 15 on the rocking axis of the armature 8 betweenthe legs 8a and 8b.

Operative retention of the armature 8 on the yoke arm la by the spring 2is effected by extension of the detent finger portion 3 through alongitudinal slot aperture 9 in the armature leg 8a and the bightportion of the leg 3b to engagewith a partially struck out tooth ortongue 10 offset obliquely inwardly from the bight end portion of thearmature leg 8b to be received in the yoke arm recess 4. The tongue lit)and the recess 4 are of complementary width so that the tongue is freelyreceived in the recess 4 but is held against any more than slightlateral movement in the recess to hold the armature against lateraldisplacement. In length, the tongue 10 is proportioned so that a fineline thrust edge surface 14 thereof aligned with the oppositely facingsurface l5, and thereby in the assembly also aligned with the fulcrumsurface 16, is engaged with tensioned thrust line contact by the springdetent finger 3. This retains the armature in place but permits thearmature to rock freely as it is activated and deactivated, and withminimal frictional resistance at the contact between the finger 3 andthe gripped edge 14.

Means are provided enabling straight line assembly of the armature 8with the yoke arm lla, as indicated by the directional arrow lll in FIG.ll. To this end, the finger 3 is provided with an angularly upwardly andoutwardly turned cam terminal 5 which is adapted in relative assemblymovement of the yoke leg 1a and the armature 8 in the straight lineindicated by the arrow ll 3 and reception of the spring finger 3 in theaperture 9 to engage a complementary cam surface a provided by the endof the tongue 10 which causes the spring 2 to be deflected upwardly asviewed in FIGS. 1 and 2 until the finger rides beyond the tongue edge 14whereupon the finger 3 snaps into the retaining engagement with thetongue 10, pressing the bight bearing surface of the armature intorocking bearing engagement with the bearing fulcrum 16;

In order to lock the armature 8 against unintentional separation fromthe yoke l, interlock means are provided comprising laterally projectinglocking lug extensions on the cam terminal 5 of the spring 2 and whichare movable in assembly over cam leading surfaces 12 provided on the leg8b of the armature 8 at opposite sidesof the tongue 10 and generallyaligned with the cam surface 10a of the tongue 10. The length of thespring finger portion 3 and the terminal cam flange 5 together is suchthat as the armature 8 attains a full assembly with the yoke arm la, thelatching or locking projection 6 will clear the outer ends of the camlead surfaces l2 and move by reason of tensioned deflection of thespring 2 into locking opposition engagement with shoulders 13 at theopposite sides of the space from which the tongue 10 has been pressed.

It will be understood, of course, that the relationship between thelatching projection shoulder elements 6 and the locking shoulders 13 issuch that there is an ample freedom for easy pivotal rocking movement ofthe retaining finger 3 and the bearing edge 14, while nevertheless therelationship is close enough to assure that the armature 8 will be heldagainst unintentional longitudinal displacement from the yoke l.Nevertheless, should it be desired to remove the armature 8, that can bedone quickly and expeditiously by lifting the spring terminal flange 5to flex the spring away from the tongue 10 and then sliding the armaturefree from the yoke arm la by a relative longitudinal separating movementwherein the spring 2 will be withdrawn through the slot aperture 9.Therefore, not only can the armature 8 be quickly assembled by astraight line assembly maneuver as indicated by the arrow 11, withautomatic snap retention by the spring 2, but straight line separationcan also be effected by simply flexibly releasing the spring from thearmature. Yet, in the assembled condition of the elements, the armature8 is thoroughly retained against any displacement from theelectromagnetic relay assembly such as from shocks to which theapparatus may be subjected. No securing operation is required of thespring 2 relative to the yoke 1 after assembly of the armature 8 hasbeen effected with the yoke 1. Neither does the spring 2 have to beremoved from the yoke 1 when the armature 8 is separated from the yoke lbut, indeed, the spring 2 remains in place on the yoke ll fullyeffective to receive the armature 8 or a replacement therefor by asimple snaptogether assembly, since there has been complete freedom fromany need to alter the structure or cause any damage to the spring 2 whenreleasing it from the armature 8 during a disassembly or separationoperation.

Although various minor modifications might be suggested by those versedin the art, it should be understood that we wish to embody within thescope of the patent warranted hereon all such embodiments as reasonablyand properly come within the scope of our contribution to the art.

We claim as our invention:

1. An electromagnet relay assembly, including a yoke member providedwith a fulcrum surface, an armature having a bearing surface rockablyengaging said fulcrum surface, a thrust surface on said armature facingoppositely to said bearing surface, a retaining leaf spring secured tosaid yoke member and having a spring detent portion in snap-on retainingengagement with said thrust surface and tensionably thrusting againstsaid thrust surface and thereby pressing said bearing surface againstsaid fulcrum surface, said armature having a rigid tongue providing saidthrust surface and offset relative to a face of said armature, said yokemember having a complementary recess into which the tongue projects,said spring detent portion overlying said recess and retaining saidtongue in the recess, said armature being of generally L-shaped providedwith a body leg overlying the yoke member and a pole leg angularlyrelated to said body leg, said bearing surface being provided at thebight at juncture of said legs, said tongue being offset into said bightwith said thrust surface and said bearing surface in alignment, saidlegs having a clearance slot opening extending across said bight, andsaid detent portion of the spring extending into said opening, saiddetent portion including a thrust surface engaging finger and a camterminal flange at the tip of said finger, said tongue having a camsurface leading to said thrust surface and engageable with said camterminal flange to lift the detent portion tensionably over said thrustsurface during a longitudinal relative assembly movement of the armatureand yoke member, the improvement comprising:

said terminal cam flange being of a length to project outwardly fromsaid opening and having inwardly facing interlock shoulder means thereonin locking confrontation with outwardly facing locking shoulder means onsaid armature and preventing unintentional relative longitudinalseparation of the armature and the yoke member.

2. An assembly according to claim 1, including leadin surfaces extendingoutwardly at the sides of and in general alignment with said cam surfaceof the tongue for guiding said cam flange interlock shoulder means tosaid outwardly facing locking shoulder means during the longitudinalrelative assembly movement of the armature and the yoke member.

3. An assembly according to claim 1, said locking shoulder means on saidflange comprising lateral projections thereon, and said shoulder meanson the armature comprising outwardly facing surfaces thereon alongsidesaid opening.

4. An assembly according to claim 1, said armature including leading camsurface for guiding said shoulder means of the cam flange to theshoulder means of the armature during relative assembly movement of thearmature and the yoke member.

5. An assembly according to claim 4, said tongue cam surface and saidleading cam surface extending in a common plane upwardly and outwardlyrelative to said armature where the body leg of the armature extendsgenerally horizontally and faces upwardly.

6. An electromagnet relay assembly, including a yoke member providedwith a fulcrum surface, an armature having a bearing surface rockablyengaging said fulcrum surface, a thrust surface on'said armature facingoppositely to said bearing surface, a retaining leaf spring secured tosaid yoke member and having a spring detent portion in snap-on retainingengagement with said thrust surface and tensionably thrusting againstsaid thrust surface and thereby pressing said bearing surface againstsaid fulcrum surface, said armature having a clearance aperture thereinthrough which said spring detent portion extends, the improvementcomprising:

said spring detent portion having interlock shoulder means;

and said armature having interlock shoulder surface facing toward saidinterlock shoulder means and preventing unintentional relativeseparation of said armature and said yoke member;

said interlock shoulder means being releasable from v said shouldersurface by manual springing of said leaf spring.

7. An assembly according to claim 6, wherein said spring detent portionincludes a retaining finger in engagement with said thrust surface, anda cam terminal flange portion turned relative to said finger for cammingover said thrust surface during relative assembly movement of saidarmature and said thrust member, and said interlock shoulder meanscomprise lateral projections on said cam terminal flange portion.

d. An assembly according to claim 6, said armature having a rigid tongueproviding said thrust surface and struck inwardly from said opening andwith said thrust surface offset relative to a front face of saidarmature, said tongue providing a cam surface extending up- 6 wardly andoutwardly considered with respect to the armature and leaf spring lyinggenerally horizontally and facing upwardly, said interlock surface ofthe armature extending upwardly above said thrust surface of the tongue,and cam surface means provided on the armature in generally the sameplane as said tongue cam surface and leading to said locking surface ofthe armature for leading said interlock shoulder means to said lockingshoulder surface during relative assembly movement of the armature andthe yoke member, and

said interlock shoulder means snapping automatically into interlockingrelation to said locking surface at completion of the relative assemblymovement.

9. An assembly according to claim 3, said clearance slot being widerthan said tongue to clear said shoulder projections for movement intointerlocking relation with said shoulder means on the armature duringsaid longitudinal relative assembly movement.

10. An assembly according to claim 3, said locking shoulder meanslateral projections extending outwardly sufficiently relative to saidshoulder means on the armature in the fully assembled relationship ofthe armature with the yoke to permit free rocking of the armature aboutsaid fulcrum surface, but said projections and said outwardly facingsurfaces being close enough together to prevent unintentional separationof the armature and yoke member.

l l i l=

1. An electromagnet relay assembly, including a yoke member providedwith a fulcrum surface, an armature having a bearing surface rockablyengaging said fulcrum surface, a thrust surface on said armature facingoppositely to said bearing surface, a retaining leaf spring secured tosaid yoke member and having a spring detent portion in snap-on retainingengagement with said thrust surface and tensionably thrusting againstsaid thrust surface and thereby pressing said bearing surface againstsaid fulcrum surface, said armature having a rigid tongue providing saidthrust surface and offset relative to a face of said armature, said yokemember having a complementary recess into which the tongue projects,said spring detent portion overlying said recess and retaining saidtongue in the recess, said armature being of generally L-shaped providedwith a body leg overlying the yoke member and a pole leg angularlyrelated to said body leg, said bearing surface being provided at thebight at juncture of said legs, said tongue being offset into said bightwith said thrust surface and said bearing surface in alignment, saidlegs having a clearance slot opening extending across said bight, andsaid detent portion of the spring extending into said opening, saiddetent portion including a thrust surface engaging finger and a camterminal flange at the tip of said finger, said tongue having a camsurface leading to said thrust surface and engageable with said camterminal flange to lift the detent portion tensionably over said thrustsurface during a longitudinal relative assembly movement of the armatureand yoke member, the improvement comprising: said terminal cam flangebeing of a length to project outwardly from said opening and havinginwardly facing interlock shoulder means thereon in lockingconfrontation with outwardly facing locking shoulder means on saidarmature and preventing unintentional relative longitudinal separationof the armature and the yoke member.
 2. An assembly according to claim1, including leadin surfaces extending outwardly at the sides of and ingeneral alignment with said cam surface of the tongue for guiding saidcam flange interlock shoulder means to said outwardly facing lockingshoulder means during the longitudinal relative assembly movement of thearmature and the yoke member.
 3. An assembly according to claim 1, saidlocking shoulder means on said flange comprising lateral projectionsthereon, and said shoulder means on the armature comprising outwardlyfacing surfaces thereon alongside said opening.
 4. An assembly accordingto claim 1, said armature including leading cam surface for guiding saidshoulder means of the cam flange to the shoulder means of the armatureduring relative assembly movement of the armature and the yoke member.5. An assembly according to claim 4, said tongue cam surface and saidleading cam surface extending in a common plane upwardly and outwardlyrelative to said armature where the body leg of the armature extendsgenerally horizontally and faces upwardly.
 6. An electromagnet relayassembly, including a yoke member provided with a fulcrum surface, anarmature having a bearing surface rockably engaging said fulcrumsurface, a thrust surface on said armature facing oppositely to saidbearing surface, a retaining leaf spring secured to said yoke member andhaving a spring detent portion in snap-on retaining engagement with saidthrust surface and tensionably thrusting against said thrust surface andthereby pressing said bearing surface against said fulcrum surface, saidarmature having a clearance aperture therein through which said springdetent portion extends, the improvement comprising: said spring detentportion having interlock shoulder means; and said armature havinginterlock shoulder surface facing toward said interlock shoulder meansand preventing unintentional relative separation of said armature andsaid yoke member; said interlock shoulder means being releasable fromsaid shoulder surface by manual springing of said leaf spring.
 7. Anassembly according to claim 6, wherein said spring detent portionincludes a retaining finger in engagement with said thrust surface, anda cam terminal flange portion turned relative to said finger for cammingover said thrust surface during relativE assembly movement of saidarmature and said thrust member, and said interlock shoulder meanscomprise lateral projections on said cam terminal flange portion.
 8. Anassembly according to claim 6, said armature having a rigid tongueproviding said thrust surface and struck inwardly from said opening andwith said thrust surface offset relative to a front face of saidarmature, said tongue providing a cam surface extending upwardly andoutwardly considered with respect to the armature and leaf spring lyinggenerally horizontally and facing upwardly, said interlock surface ofthe armature extending upwardly above said thrust surface of the tongue,and cam surface means provided on the armature in generally the sameplane as said tongue cam surface and leading to said locking surface ofthe armature for leading said interlock shoulder means to said lockingshoulder surface during relative assembly movement of the armature andthe yoke member, and said interlock shoulder means snappingautomatically into interlocking relation to said locking surface atcompletion of the relative assembly movement.
 9. An assembly accordingto claim 3, said clearance slot being wider than said tongue to clearsaid shoulder projections for movement into interlocking relation withsaid shoulder means on the armature during said longitudinal relativeassembly movement.
 10. An assembly according to claim 3, said lockingshoulder means lateral projections extending outwardly sufficientlyrelative to said shoulder means on the armature in the fully assembledrelationship of the armature with the yoke to permit free rocking of thearmature about said fulcrum surface, but said projections and saidoutwardly facing surfaces being close enough together to preventunintentional separation of the armature and yoke member.